Contradiction with Deuteronomy 20:16-17
This verse commands the Israelites to destroy certain nations completely, which contrasts with the listing of defeated kings in Joshua 12, implying some were not utterly destroyed.
Deuteronomy 20:16-17: But of the cities of these people, which the LORD thy God doth give thee [for] an inheritance, thou shalt save alive nothing that breatheth:
Contradiction with 1 Samuel 15:3
God commands Saul to completely destroy the Amalekites, showing a divine directive for total destruction, unlike the mere listing of defeated kings in Joshua 12:9.
1 Samuel 15:3: Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass.